Identification of specific tumor antigens by means of the selection of cdna libraries with sera and the use of said antigena in the treatment of tumors

ABSTRACT

A method is described for the identification of specific tumour antigens by means of the selection of CND display libraries by using sera, characterised in that said selection is accomplished with the phage display technique, and in particular said selection is accomplished by means of the SEREX technique (serological analysis of autologous tumor antigens through the expression of recombinant cDNA). The method according to the invention described herein advantageously combines the SEREX approach with the potency of the phage display technique defined above, at the same time avoiding the drawbacks characteristic of the SEREX technique. The so identified antigens are useful for the preparation of medicaments for the treatment of tumors.

The invention described herein relates to a method for the identification of specific tumor antigens by means of selection with sera of cDNA libraries derived from tumor cell lines or from subjects suffering from tumors, and particularly for the therapy of tumors.

The invention described herein provides compounds, methods for their preparation, methods for their use, and compositions containing them, suitable for industrial application in the pharmaceutical field.

In particular, but not exclusively, the invention described herein relates to the field of tumor treatment.

BACKGROUND OF THE INVENTION

Tumor therapy is practised according to multiple approaches of tumor attack. Other then the use of cytotoxic substances, immunotherapeutic approach is gaining even higher interest.

In this context, tumor immunotherapy knows a constant increase of efforts in research, with the aim to find more effective methods for the identification of specific tumor antigens, useful for the preparation of medicaments for the treatment of tumors. In particular, antitumor vaccines constitute a kind of immunotherapy having the goal to stimulate immune system of the same patient to react against tumor antigens. For this reason, the research has recently focused also on the target of identifying, isolating and cloning specific tumor-associated antigens, which can be recognized by the host immune system.

A review of arguments and related problems can be found, for example in EP 0 496 074 and WO 00/25813 and the references cited therein.

The identification of tumor antigens may then provide new and better target-specific therapeutic means and more effective methods for the treatment of tumors. More or less specific tumor antigens are known, which have been obtained using tumor cells as antigens-immunogens to stimulate antibodies in laboratory animals. Also known are a number of tumor antigens that stimulate the formation of antibodies in the patients themselves (for example, p53 mutants, HER-2/neu, CEA, PSA). Their identification, however, is difficult when using conventional methods.

The recent development of a method of analysing (screening) cDNA libraries with sera of patients suffering from various types of tumors, known as SEREX (serological analysis of autologous tumor antigens through the expression of recombinant cDNA, see P.N.A.S. 92, 11810-1995), has led to the identification of a large number of tumor antigens.

The SEREX technology is undoubtedly useful for identifying new tumor antigens, but it presents a number of drawbacks consisting in the very laborious nature of the library screening operations, the high degree of background noise and the large amounts of material necessary.

Since 1993, the year the first tumor antigen (carbonic anhydrase) was characterised, more than 600 different proteins specifically expressed in tumors and to which an immune response is generated have been identified (M. Pfreundschuch et al. Cancer Vaccine Week, International Symposium, Oct. 5-9, 1998, S03) and this number is destined to rise still further further [as today SEREX database contains 1695 public sequences (www.licr.org/SEREX.html)]. It is interesting to note that 20-30% of the sequences isolated are as yet unknown gene products.

Further research, however, is necessary to improve the techniques for identifying specific tumor antigens for the treatment of tumors.

ABSTRACT OF THE INVENTION

It has now been found that a combination of the SEREX technique and phage display, a strategy based on the selection of libraries in which small protein domains are displayed on the surface of bacteriophages, within which the corresponding genetic information is contained, provides a method for the identification of specific tumor antigens by means of the selection of cDNA display libraries with sera. Using this method it proves possible to identify antigens from very large libraries (i.e. which express a large number of different sequences). The antigens thus identified make it possible to obtain specific ligands, which in turn can be used as contrast media.

Therefore, one object of the invention described herein are specific tumor antigens obtainable by a method comprising the identification by means of the selection of cDNA display libraries with sera, said method being characterised in that said selection is accomplished using the phage display technique.

The purpose of the invention described herein is to provide tumor antigens useful for the preparation of medicaments for the treatment of tumor.

Said medicaments are preferably in the form of vaccines.

In another embodiment of the present invention, said antigens are used for the preparation of specific ligands, which can be used for the preparation of medicaments, such as vaccines, or as carriers of antitumor drugs, for example cytotoxic agents or radionuclides.

DETAILED DESCRIPTION OF THE INVENTION

The invention described herein comprises the construction of cDNA libraries from tumor cells, obtained both from biopsies (preferable fresh) and from cultured tumor lines, the selection (screening) of such libraries with autologous and heterologous patient sera to identify tumor antigens, including new ones, the characterisation of said antigens, the generation of specific ligands for said tumor antigens (for example, recombinant human antibodies or humanised recombinant murine antibodies), and the preparation of target-selective medicaments incorporating the ligands generated, optionally carrying antitumor active agents.

The method, according to the invention described herein, advantageously combines the SEREX approach with the potency of the phage-display technique defined above, at the same time avoiding the drawbacks characteristic of the SEREX technique, as outlined above.

What is meant by “phage display” is, as understood by the person of ordinary skill in the art, a strategy based on the selection of libraries in which small protein domains are exposed on the surface of bacteriophages within which is contained the corresponding genetic information.

The method implemented according to the invention described herein provides for the first time new and advantageous analysis possibilities:

-   -   the use of smaller amounts of serum to identify tumor antigens,         selecting, prior to screening, the library with sera of patients         suffering from tumors, in such a way as to reduce their         complexity, enriching it with those clones that express specific         antigens;     -   owing to technical problems, the direct screening of cDNA         libraries, as realised with the state of the art technique, does         not allow analysis of a large number of clones (more than         approximately one million clones), and thus makes it unsuitable         to exploit all the potential of recombinant DNA technology. With         the method according to the invention, it is, in fact, possible         to construct and analyse libraries 10-100 times larger than         those traditionally used in SEREX, thus increasing the         likelihood of identifying even those antigens which are present         to only a limited extent;     -   lastly, the possibility of effecting subsequent selection cycles         using sera of different patients or mixtures of sera facilitates         the identification of cross-reactive tumor antigens, which         constitute one of the main objectives of the invention described         herein.

In a library of cDNA cloned in a non-directional manner, it is expected that approximately one-sixth (16.7%) of the proteins produced will be correct. The enrichment of this type of library with the true translation product is the real task of expression/display libraries. The invention described herein also provides a new vector for the expression of cDNA and the display of proteins as fusions with the amino-terminal portion of bacteriophage lambda protein D (pD) with limited expression of “out-of-frame” proteins. According to the vector design, the phage displays the protein fragment on the surface only if its ORF (“Open Reading Frame”) coincides with that of pD. The average size of the fragments of cloned DNA in our libraries is 100-600 b.p. (base pairs), and for statistical reasons, most of the “out-of-frame” sequences contain stop codons that do not allow translation of pD and display on the phage surface. In this case, the copy of the lambda genome of wild-type gpD supports the assembly of the capsid. The new expression/display vector (λKM4) for cDNA libraries differs from the one used in SEREX experiments (λgt11) in that the recombinant protein coded for by the cDNA fragment is expressed as a fusion with a protein of the bacteriophage itself and thus is displayed on the capsid.

For each library, messenger RNA of an adequate number of cells, e.g. 10⁷ cells, is purified, using common commercially available means, from which the corresponding cDNA has been generated. The latter is then cloned in the expression/display vector λKM4. The amplification of the libraries is accomplished by means of normal techniques known to the expert in the field, e.g. by plating, growth, elution, purification and concentration.

The libraries are then used to develop the conditions required for the selection, “screening” and characterisation of the sequences identified. A library of the phage-display type, constructed using cDNA deriving from human cells, allows the exploitation of selection by affinity, which is based on the incubation of specific sera with collections of bacteriophages that express portions of human proteins (generally expressed in tumors) on their capsid and that contain within them the corresponding genetic information. Bacteriophages that specifically bind the antibodies present in the serum are easily recovered, in that they remain bound (by the antibodies themselves) to a solid support; the non-specific ones, on the other hand, are washed away.

The “screening”, i.e. the direct analysis of the ability of the single phage clones to bind the antibodies of a given serum, is done only at a later stage, when the complexity of the library (i.e. the different number of sequences) is substantially reduced, as a result of the selection.

The use of selection strategies allows faster analysis of a large number of different protein sequences for the purposes of identifying those that respond to a particular characteristic, for example, interacting specifically with antibodies present in the sera of patients with tumors.

Selection by affinity is based on the incubation of specific sera with collections of bacteriophages that express portions of human proteins (generally expressed in tumors) on their capsid and that contain within them the corresponding genetic information. The bacteriophages that specifically bind antibodies present in the serum are easily recovered in that they remain bound (by the antibodies themselves) to a solid support; the non-specific ones, on the other hand, are washed away.

The “screening”, i.e. the direct analysis of the ability of the single phage clones to bind the antibodies of a given serum, is done only at a later stage, when the complexity of the library (i.e. the different number of sequences) is substantially reduced, as a result of the selection. This makes it possible to reduce the work burden and, above all, to use a lower amount of serum for each analysis.

The direct “screening” of a classic cDNA library, in fact, entails the use of large amounts of serum, which are not always easy to procure; in order to analyse the whole complexity of a library (about 10⁶ different sequences), one would have to incubate with the sera different filters onto which recombinant proteins, expressed in lysis plaques of infected bacteria, have been transferred: on each filter, it is possible to analyse no more than 10⁴ plaques (therefore, at least 100-1000 filters having 15 cm diameter would be necessary) and a 5-10 ml serum volume is used for each filter at a 1:1000 serum dilution (0.5-10 ml total serum).

This strategy, moreover, does not allow the identification of antigens which are present in only slight amounts in the library or are recognised by antibodies present in low concentrations.

On the contrary, affinity selection allows the analysis of more than 10¹¹ phage particles in a small volume (0.1-1.1 ml), thereby reducing the required amount of serum: with only 10 μl of serum for each reaction, one can work with a concentration of 10- to 100-fold greater than the one used direct screening, consequently increasing also the probability of identifying those antigens regarded as difficult (considering that one normally performs two selection cycles and one screening on 82 mm filters, the total overall consumption of serum in this case is only 40 μl).

It is thus possible to use selection strategies that favour the identification of antigens capable of interacting with the antibodies present in sera of different patients affected by the same type of tumor (cross-reactive antigens).

Various protocols can be adopted based on the use of different solid supports. These protocols are known to experts in the field. Various protocols can be used based on the use of different solid supports, such as, for example:

-   -   sepharose: the serum antibodies with the bound phages are         attached to a sepharose resin coated with protein A which         specifically recognises the immunoglobulins. This resin can be         washed by means of brief centrifuging operations to eliminate         the aspecific component;     -   magnetic beads: the serum antibodies with the bound phages are         recovered using magnetic beads coated with human anti-IgC         polyclonal antibodies. These beads are washed, attaching them to         the test tube wall with a magnet;     -   Petri dishes: the serum antibodies with the bound phages are         attached to a Petri dish previously coated with protein A. The         dish is washed by simply aspirating the washing solution.

The invention will now be illustrated in greater detail by means of examples and figures, FIG. 1 representing the map of vector λKM4.

EXAMPLE

Phages and Plasmids:

Plasmid pGEX-SN was constructed by cloning the DNA fragment deriving from the hybridisation of the synthetic oligonucleotides K108 5′-GATCCTTACTAGTTTTAGTAGCGGCCGCGGG-3′ and K109 5′-AATTCCCGCGGCCGCTACTAAAACTAGTAAG-3′ in the BamHI and EcoRI sites of plasmid pGEX-3X (Smith D. B. and Johnson K. S. Gene, 67(1988) 31-40).

Plasmid pKM4-6H was constructed by cloning the DNA fragment deriving from the hybridisation of the synthetic oligonucleotides K106 5′-GACCGCGTTTGCCGGAACGGCAATCAGCATCGTTCACCACCACCACCACCACTAATAGG-3′ and K107 5′-AATTCCTATTAGTGGTGGTGGTGGTGGTGAACGATGCTGATTGCCGTTCCGGCAAACGCG-3′ in the RsrII and EcoRI sites of plasmid pKM4.

Selection By Affinity

Falcon plates (6 cm, Falcon 1007) were coated for one night at 4° C. with 3 ml of 1 μg/ml of protein A (Pierce, #21184) in NaHCO₃ 50 mM, pH 9.6. After discarding the coating solution, the plates were incubated with 10 ml of blocking solution (5% dry skimmed milk in PBS×1, 0.05% Tween 20) for 2 hours at 37° C. 10 μl of human serum were preincubated for 30 minutes at 37° C. under gentle agitation with 10 μl of BB4 bacterial extract, and 10 μl of MgSO₄ 1M in 1 ml of blocking solution. Approximately 10¹⁰ phage particles of the library were added to the serum solution for a further 1 hour incubation at 37° C. under gentle agitation. The incubation mixtures were plated on plates coated with protein A and left for 30 minutes at room temperature. The plates were rinsed several times with 10 ml of washing solution (1×PBS, 1% Triton, 10 mM MgSO₄). The bound phages were recovered by infection of BB4 cells added directly to the plate (600 μl per plate). 10 ml of molten NZY-Top Agar (48-50° C.) were added to the infected cells and immediately poured onto NZY plates (15 cm). The next day, the phages were collected by incubating the plates with agitation with 15 ml of SM buffer for 4 hours at 4° C. The phages were purified by PEG and NaCl precipitation and stored in one tenth of the initial volume of SM with 0.05% sodium azide at 4° C.

Immunoscreening

The phage plaques of the bacterial medium were transferred onto dry nitrocellulose filters (Schleicher & Schuell) for 1 hour at 4° C. The filters were blocked for 1 hour at room temperature in blocking buffer (5% dry skimmed milk in PBS×1, 0.05% Tween 20). 20 μl of human serum were preincubated with 20 μl of BB4 bacterial extract, 10⁹/ml of wild-type lambda phage in 4 ml of blocking buffer. After discarding the blocking solution, the filters were incubated with serum solution for 2 hours at room temperature with agitation. The filters were washed several times with PBS×1, 0.05% Tween 20 and incubated with human anti-IgG secondary antibodies conjugated with alkaline phosphatase (Sigma A 2064) diluted 1:5000. Then the filters were washed as above, rinsed briefly with substrate buffer (100 mM Tris-HCl, pH 9.6, 100 mM NaCl, 5 mM MgCl₂). Each filter was incubated with 10 ml of substrate buffer containing 330 mg/ml nitro blue tetrazolium, 165 mg/ml 5-bromo-4-chloro-3-indolylphosphate. Reaction was stopped by water washing.

Preparation of Lambda Phase on Large Scale (From Lysogenic Cells)

The BB4 cells were grown up to OD₆₀₀=1.0 in LB containing maltose 0.2% with agitation, recovered by centrifugation and resuspended in SM buffer up to OD₆₀₀=0.2. 100 μl of cells were infected with lambda with a low multiplicity of infection, incubated for 20 minutes at room temperature, plated on LB agar with ampicillin and incubated for 18-20 hours at 32° C. The next day, a single colony was incubated in 10 ml of LB with ampicillin for one night at 32° C. with agitation. 500 ml of fresh LB with ampicillin and MgSO₄ 10 mM were inoculated with 5 ml of the overnight culture in a large flask and grown at 32° C. up to OD₆₀₀=0.6 with vigorous agitation. The flask was incubated for 15 minutes in a water bath at 45° C., then incubated at 37° C. in a shaker for a further 3 hours. 10 ml of chloroform were added to the culture to complete the cell lysis and the mixture was incubated in the shaker for another 15 minutes at 37° C. The phage was purified from the lysate culture ac-cording to standard procedures (Sambrook, J., Fritsch, E. F. & Maniatis, T. (1989) Molecular Cloning, Cold Spring Harbor Laboratory Press, Cold Spring Harbor).

The phage lysates for ELISA were prepared from the lysogenic cells by means of a similar procedure, but without the addition of chloroform. After precipitation with NaCl and PEG, the bacteriophage pellet was resuspended in one tenth of the starting volume of SM buffer with sodium azide (0.05%) and stored at 4° C.

Lambda ELISA

Multi-well plates (Immunoplate Maxisorb, Nunc) were coated for one night at 4° C. with 100 μl/well of anti-lambda polyclonal antibodies at a 0.7 μg/ml concentration in NaHCO₃ 50 mM, pH 9.6. After discarding the coating solution, the plates were incubated with 250 μl of blocking solution (5% dry skimmed milk in PBS×1, 0.05% Tween 20). The plates were washed twice with washing buffer (PBS×1, Tween 20). A mixture of 100 μl of blocking buffer and phage lysate (1:1) was added to each well and incubated for 1 hour at 37° C. 1 ml of human serum was incubated for 30 minutes at room temperature with 10⁹ plaque forming units (pfu) of phage λKM4, 1 μI of rabbit serum, 1 μl of BB4 extract, 1 μl of FBS in 100 μl of blocking buffer. The plates were washed after incubation with phage lysate and incubated with serum solution for 60 minutes at 37° C. The plates were then washed and goat anti-human HRP conjugated antibody was added (Jackson ImmunoResearch Laboratories), at a dilution of 1:20000, in a blocking buffer/secondary antibody mixture (1:40 rabbit serum in blocking solution). After a 30 minute incubation, the plates were washed and peroxidase activity was measured with 100 μl of TMB liquid substrate system (Sigma). After 15 minutes development, the reaction was stopped with 25 μl of H₂SO₄ 2M. The plates were read with an automatic ELISA plate reader and the results were expressed as A=A_(450nm)-A_(620nm). The ELISA data were measured as the mean values of two independent assays.

Construction of λKM4

Plasmid pNS3785 (Hoess, 1995) was amplified by inverse PCR with the oligonucleotide sequences KT1 5′-TTTATCTAGACCCAGCCCTAGGAAGCTTCTCCTGAGTAGGACAAATCC-3′ bearing sites XbaI and AvrII (underlined) and KT2 5′-GGGTCTAGATAAAACGAAAGGCCCAGTCTTTC-3′ bearing XbaI for subsequent cloning in lambda phage. In the inverse PCR, a mixture of Taq polymerase and Pfu DNA polymerase was used to increase the fidelity of the DNA synthesis. Twenty-five amplification cycles were performed (95° C.-30 sec, 55° C.-30 sec, 72° C.-20 min). The self-ligation of the PCR product, previously digested with XbaI endonuclease, gave rise to plasmid pKM3. The lambda pD gene was amplified with PCR from plasmid pNS3785 using the primers K51 5′-CCGCCTTCCATGGGTACTAGTTTTAAATGCGGCCGCACGAGCAAAGAAACCTTTAC-3′ containing the restriction sites NcoI, SpeI, NotI (underlined) and K86 5′-CTCTCATCCGCCAAAACAGCC-3′. The PCR product was purified, digested with NcoI and EcoRI restriction endonucleases and re-cloned in the NcoI and EcoRI sites of pKM3, resulting in plasmid pKM4 bearing only the restriction sites SpeI and Not I at extremity 5′ of gpD. The plasmid was digested with XbaI enzyme and cloned in the XbaI site of lambda phage λDam15imm21nin5 (Hoess, 1995) (FIG. 1).

Construction of cDNA Libraries

mRNA was isolated from 10⁷ MCF-7 cells (T1 library) or from 0.1 g of a solid tumour sample (T4 library) using a QuickPrep Micro mRNA Purification Kit (Amersham Pharmacia Biotech) according to the manufacturer's instructions. Double-stranded cDNA was synthesised from 5 μg of poly(A)+ RNA using the TimeSaver cDNA Synthesis Kit (Amersham Pharmacia Biotech). Random tagged priming was performed as described previously (Santini, 1986). From 500 ng of double-stranded cDNA the first strand of cDNA copy was synthesised by using the random tagged primer 5′-GCGGCCGCTGG(N)₉-3′, and the second-strand cDNA copy by using the primer 5′-GGCGGCCAAC(N)₉-3′. The final cDNA product was amplified using oligonucleotides bearing SpeI with three different reading frames and NotI sites to facilitate cloning in the λKM4 lambda vector (5′-GCACTAGTGGCCGGCCAAC-3′, 5′-GCACTAGTCGGCCGGCCAAC-3′, 5′-GCACAGTCGGGCCGGCCAAC-3′ and 5′-GGAGGCTCGAGCGGCCGCTGG-3′). The PCR products were purified on Quiaquick columns (Quiagen) and filtered on Microcon 100 (Amicon) to eliminate the small DNA fragments, digested with SpeI, NotI restriction enzymes, and, after extraction with phenol, filtered again on Microcon 100.

Vector λKM4 was digested with SpeI/NotI and dephosphorylated, and 8 ligation mixtures were prepared for each library, each containing 0.5 mg of vector and approximately 3 ng of insert. After overnight incubation at 4° C. the ligation mixtures were packaged in vitro with a lambda packaging kit (Ready-To-Go™ Lambda Packaging Kit, Amersham Pharmacia Biotech) and plated in top-agar on 100 (15 cm) NZY plates. After overnight incubation, the phage was eluted from the plates with SM buffer, purified, concentrated and stored at −80° C. in 7% DMSO SM buffer.

The complexity of the two libraries, calculated as total independent clones with inserts, was 10⁸ for the T1 library and 3.6×10⁷ for the T4 library.

Selection by Affinity

For the identification of specific tumour antigens two different affinity selection procedures were used. The first consisted of two panning cycles with a positive serum (i.e. deriving from a patient suffering from tumour pathology), followed by an immunological screening procedure carried out with the same serum, or, alternatively, by analysis of clones taken at random from the mixture of selected phages. A second procedure used a mixture of sera from different patients for the selection, both for panning and for screening, for the purposes of increasing the efficacy of selection of cross-reactive antigens.

The T1 library was selected with 10 positive sera (B9, B11, B13, B14, B15, B16, B17, B18, B19, and B20), generating, after a single selection round, the corresponding pools p9^(I), p11^(I), p13^(I), p14^(I), p15^(I), p16^(I), p17^(I), p18^(I), p19^(I), and p20^(I). Each pool was then subjected to a second affinity selection round with the same serum, according to the first strategy mentioned above, generating a second series of pools (called p9^(II), p11^(II), p13^(II), p14^(II), p15^(II), p16^(II), p17^(II), p18^(II), p19^(II), and p20^(II)). Some of the pools tested in ELISA demonstrated increased reactivity with the corresponding serum, thus confirming the efficacy of the library and of the affinity selection procedure. Individual clones from pools with increased reactivity (p9^(II), p13^(II), p15^(II), p19^(II), p20^(II)) were isolated by immunoscreening with sera used for the selection.

The second procedure mentioned above was applied to the p13^(II) pool, subjecting it to a third selection round with a mixture of sera with the exception of B13 (B11, B14, B15, B16, B17, B18, B19, and B20), and thus selecting cross-reactive clones. The resulting pool (p13^(III)) was assayed by ELISA with the same mixture of sera used in the panning. Individual clones from the pool were isolated by immunoscreening with mix ΔB13 (B11, B14, B15, B16, B17, B18, B19, and B20), which made it possible to isolate further positive clones.

Affinity selection experiments were also conducted with the T4 library (and also with the T1 library using different sera) according to the same methodology described here.

Multiple Immunological Screening (Pick-Blot Analysis)

The individual phage clones which were positive in the immunological screening were isolated and the eluted phages were grown on the lawn of bacteria on plates of 15 cm by picking in arrayed order. The plaques were transferred onto nitrocellulose membranes and subjected to analysis with different positive and negative sera. For the purposes of making the method more robust and reproducible, a Genesys Tekan robotic station was used to pick phages on the plates, which allowed analysis of up to a maximum of 396 individual clones on a membrane of 11×7.5 cm, or a lower number of clones repeatedly picked on the same plate cutting the membrane into smaller pieces before incubation with the sera.

Characterisation of Positive Clones

The clones that presented multiple reactivity, or a greater specificity for the sera of tumour patients as compared to that of healthy donors, were subsequently sequenced and compared with different databases of sequences currently available (Non-Redundant Genbank CDS, Non-Redundant Database of Genbank Est Division, Non-Redundant Gen-Bank+EMBL+DDBJ+PDB Sequences).

The sequences obtained can be classified in six groups:

-   -   sequences that code for epitopes of known breast tumour         antigens;     -   known sequences that code for epitopes of tumour antigens other         than those of breast tumour;     -   sequences that code for autoantigens;     -   sequences that code for known proteins which are, however, not         known to be involved either in tumours or in autoimmune         diseases;     -   sequences that code for unknown proteins (e.g. EST);     -   new sequences not yet present in the databases.

Eighty-one different sequences were identified from the T1 library (called T1-1 to T1-115), 13% of which were unknown proteins and 16% were not present in the databases. Twenty-one sequences were identified from the T4 library (called T4-1 to T4-38), 40% of which were not to be found in the databases. The following table shows, by way of an example, the sequences of some of the clones selected: Name of clone Sequence Identification Classification T1-2 ATGGGTACTAGTCGGCCGGCCAA Intestinal Tumor CATCACTCCCACCAATACAATGA mucin antigen CTTCTATGAGAACTACAACCTAT TGGCCCACAGCCACAATGATGGA ACCACCTTCATCCACTGTATCAA CTACAGGCAGAGGTCAGACCACC TTTCCAGCTCTACAGCCACATTC CCCAATACCAAACACCCCAGCGG CCGC T1-17 ATGGGTACTAGTCGGGCCGGCCA DNA-topo- Tumor ACTTGTTGAAGAACTGGATAAAG isomerase antigen- TGGAATCTCAAGAACGAGAAGAT II beta malignant GTTCTGGCTGGAATGTCTGGAAA mesothelioma ATCCTCTTTCCAAAGATCTGAAG GAGATTTTCTTTTAAGATCATTG ACCAGCGGCCGC T1-8 ATGGGTACTAGTGGCCGGCCAAC RBP-1 Tumor AAGGCAGCTGGAAGAGGTTCTCA antigen- AATTAGATCAAGAAATGCCTTTA cancer of the ACAGAAGTGAAGAGTGAACCTGA breast GGAAAATATCGATTCAAACAGTG AAAGTGAAAGAGAAGAGATAGAA TTAAAATCTCCGAGGGGACGAAG GAGAATTGCTCGAGATCCCAGCG GCCGC T1-6 ATGGGTACTAGTCGGGGCGGCCA Golgin p245 Autoantigen ACTTGAGGAGCTGCAGAAGAAAT ACCAGCAAAAGCTAGAGCAGGAG GAGAACCCTGGCAATGATAATGT AACAATTATGGAGCTACAGACAC AGCTAGCACAGAAGACGACTTTA ATCAGTGATTCGAAATTGAAAGA GCAAGAGTTCAGAGAACAGATTC ACAATTTAGAAGACCGTTTGAAG AAATATGAAAAGAATGTATATGC AACAACTGTGGGGACACCTTACA AAGGTGGCAATTTGTACCATACG GATGTCTCACTCTTTGGAGAACC TACCAGCGGCCGC T1-101 ATGGGTACTAGTCGGCCGGCCAA Human lupus Autoantigen CTTCGTGGAAATCAGTGAAGATA La protein AAACTAAAATCAGAAGGTCTCCA AGCAAACCCCTACCTGAAGTGAC TGATGAGTATAAAAATGATGTAA AAAACAGATCTGTTTATATTAAA GGCTTCCCAACTGAAGCCAGCGG CCGC T1-52 GTGGCCGGCCAACGTTATCAGAG Binding Unknown as TAGAAGTGGGCATGATCAGAAGA protein p53 tumor antigen ATCATAGAAAGCATCATGGGAAG AAAAGAATGAAAAGTAAACGATC TACATCATTGTCATCTCCCAGAA ACGGAACCAGCGGCGGC T1-35 ATGGGTACTAGTCGGGCCGGCCA Nuclear matrix Unknown as ACAAATTAGGCAGATTGAGTGTG protein tumor antigen ACAGTGAAGACATGAAGATGAGA GCTAAGCAGCTCCTGGTTGCCTG GCAAGATCAAGAGGGAGTTCATG CAACACCTGAGAATCTGATTAAT GCACTGAATAAGTCTGGATTAAG TGACCTTGCAGAAAGTCCCAGCG GCCGC T1-10 ATGGGTACTAGTGGCCGGCGAAC Ribosomal Unknown as GGCAGTAGTTCTGGAAAAGCCAC protein s3a tumor antigen TGGGGACGAGACAGGTGCTAAAG TTGAACGAGCTGATGGAGCTTCA TGGTGAAGGCAGTAGTTCTGGAA AAGCCACTGGGGACGAGACAGGT GCTAAAGTTGAACGAGCTGATGG AATGACCCCCAGCGGCCGC T1-39 ATGGGTACTAGTGGCCGGCCAAC No data GAATTATTCGAGTGCTATAGGCG CTTGTCAGGGAGGTAGCGATGAG AGTAATAGATAGGGCTCAGGCGT TTGTTGATGAGATATTTGGAGGT GGGGATGATGCACATAATTTGAA TCAACACAACTCCAGCGGCCGC T1-12 ATGGGTACTAGTCGGGCCGGCCA No data ACGTGGTATTATTTAAAAATAGC TAAAAAGGTAAACAATCCAAATG CCATTAAACAGAGAATTTTAAAA AATGAGATACTACACAGCAACAA AAACCTATGAGCTAATGCTAGAT GCAACAACACAGACCAGCGGCCG C T1-32 ATGGGTACTAGTCGGGCCGGCCA No data ACTACACGCCTTTCCACTCCACT CTACTACACTCTACTACACTACA CCCAGCGGCCGC T1-74 ATGGGTACTAGTCGGCCGGCCAA EST CAGAGAAGCTAAGCAAGTGCATC ATCAGCCACATTCAATCGAATTA ATACAGTCCAGCGGCCGC T4-2 ATGGGTACTAGTCGGCCGGCCAA EST CTCAGAGGTGTATAAGCCAACAT TGCTCTACTCCAGCGGCGGC T4-11 ATGGGTACTAGTGGCCGGCCAAC EST GGTTGGTTTTACTCTAGATTTCA CTGTCGACCCACCCAGCGGCCGC T4-19 ATGGGTACTAGTCGGGCCGGCCA No data ACTATACCGTACAACCCTAACAT ATACCAGCGGCCGC T5-8 ATGGGTACTAGTCGGGCCGGCCA AKAP protein Unknown as ACAGAGAGAGCAAGAAAAGAAAA tumour GAAGCCCTCAAGATGTTGAAGTT antigen CTCAAGACAACTACTGAGCTATT TCATAGCAATGAAGAAAGTGGAT TTTTTAATGAACTCGAGGCTCTT AGAGCTGAATCAGTGGCTACCAA AGCAGAACTTGCCAGTTATAAAG AAAAGGCTGAAAAACTTCAAGAA GAACTTTTGGTAAAAGAAACAAA TATGACATCTCTCAGAAAGACTT AAGCCAAGTTAGGGATCACCAGG GCCGC T5-13 ATGGGTACTAGTCGGGCCGGCCA SOS1 protein Unknown as ACACGCATTCGAGCAAATACCAA tumour GTCGCCAGAAGAAAATTTTAGAA antigen GAAGCTCATGAATTGAGTGAAGA TCACTATAAGAAATATTTGGCAA AACTCAGGTCTATTAATCCACGA TGTGTGCCTTTCTTTGGAATTTA TCTCACTAATCTCTTGAAAACAG AAGAAGGCAACCCTGAGGTCCTA AAAAGACATGGAAAAGAGCTTAT AAACTTTAGCAAAAGGAGGAAAG TAGCAGAAATAACAGGAGAGATC CAGCAGTACCAAAATCAGGCNTA CTGTTTACGAGTAGAATCAGATA TCAAAAGGTTCTTTGAAAACTTG AATCCGATGGGAAATAGCATGGA GAAGGAATTTACAGATTATCTTT TCAACAAATCCCTAGAAATAGAA CCACGAAAACCCAGCGGCCGC T5-15 ATGGGTACTAGTCGGGCCGGCCA EST ACAGGAGAGGTCCTTGGCCCTCT KIAA1735 GTGAACCAGGTGTCAATCCCGAG protein GAACAACTGATTATAATCCAAAG TCGTCTGGATCAGAGTTTGGAGG AGAATCAGGACTTAAAGAAGGAA CTGCTGAAATGTAAACAAGAAGC CAGAAACTTACAGGGGATAAAGG ATGCCTTGCAGCAGAGATTGACT CAGCAGGACACATCTGTTCTTCA GCTCAAACAAGAGCTACTGAGGG CAAATATGGACAAAGATGAGCTG CACAACCAGAATGTGGATCTGCA GAGGAAGCTAGATGAGAGGACCC AGCGGCCGC T5-18 ATGGGTACTAGTCGGGCCGGCCA mic oncogen, Unknown as ACCGATGTCTGGACATGGGAGTT alternative tumour TTCAAGAGGTGCCACGTCTCCAC frame antigen ACATCAGCACAACTACGCAGCGC CTCCCTCCACTCGGAAGGACTAT CCTGCTGCCAAGAGGGTCAAGTT GGACAGTGTCAGAGTCCTGAGAC AGATCAGCAACAACCGAAAATGC ACCAACCCAGCGGCCGC T6-1 ACTAGTCGGGCCGGCCAACGTTA protein kinase known as TGAGAAGTCAGATAGTAGCGATA C-binding cutaneous T- GTGAGTATATCAGTGATGATGAG protein cell CAGAAGTCTAAGAACGAGCCAGA lymphoma AGACACAGAGGACAAAGAAGGTT tumor antigen GTCAGATGGACAAAGAGCCATCT GCTGTTAAAAAAAAGCCCAAGCC TACAAACCCAGTGGAGATTAAAG AGGAGCTTAAAAGCACGCCACCA GCCAGCGGCCGC T6-2 ACTAGTCGGGCCGGCCAACTTGC not found CAGGATTCCCTCAGTAACGGCGA GTGAACAGGGAAGAACCAGCGGC CGC T6-6 ACTAGTGGGCCGGCCAACGCTGC homologous to Unknown as TCCACCCTCAGCAGATGATAATA PI-3-kinase tumour TCAAGACACCTGCCGAGCGTCTG related kinase antigen CGGGGGCCGCTTCCACCCTCAGC SMG-1 GGATGATAATCTCAAGACACCTT CCGAGCGTCAGCTCACTCCCCTC CCCCCAGCGGCCGC T6-7 ACTAGTCGGGCCGGCCAACGGGA Fucosyltransferase Unknown as ATTGGGAAGGACGGGCCTATATC tumour CCTCCTACAAAGTTCGAGAGAAG antigen ATAGAAACGGTCAAGTACCCCAC ATATCCTGAGGCTGAGAAATAAA GCTCAGATGGAAGAGATAAACGA CCAAACTCAGTTCGACCAAACTC AGTTCAAACCATTTGAGCCAAAC TGTAGATGAAGAGGGCTCTGATC TAACAAAATAAGGTTATATGAGT AGATACTCTCAGCACCAAGAGCA GCTGGGAACTGACATAGGCTTCA ATTGGTGGAATTCCTCTTTAACA AGGGCTGCAATGCCCTCATACCC ATGCACAGTACAATAATGTACTC ACATATAACATGCAAAGGTTGTT TTCTACTTTGCCCCTTTCAGTAT GTCCCCATAAGACAAACACTACC AGCGGCCGC T7-1 ACTAGTGTCCTGGAACCCACAAA EST Unknown as AGTAACCTTTTCTGTTTCACCGA KIAA1288 tumour TTGAAGCGACGGAGAAATGTAAG protein antigen AAAGTGGAGAAGGGTAATCGAGG GCTTAAAAACATACCAGACTCGA AGGAGGCACCTGTGAACCTGTGT AAACCTAGTTTAGGAAAATCAAC AATCAAAACGAATACCCCAATAG GCTGCAAAGTTAGAAAAACTGAA ATTATAAGTTACCCAAGTACCAG CGGCCGC T9-22 ATGGACTTAACAGCTGTTTACAG similar to AACATTCCACCCAACAATCACAG reverse AATATACATTCTATTTAACAGTG trascriptase CATGGAACTTTTTCCAAGATAGA homolog, CCATATGATAGGCCACAAAACAA 50% of identity GTCTCAATAAGTCTAAGAAAACT GAAATTATATCAAGTACTCTCTC AGACCACAGTGGAATAAAATTGG AAAGTAATTCCAAAAGGAACCCC CAAATCCATGCCAGCGGCCGC T11-5 ATGCCGATTGACGTTGTTTACAC EST CTGGGTGAATGGCACAGATCTTG unnamed AACTACTGAAGGAACTACAGCAG transmembrane GTCAGAGAACAGATGGAGGAGGA protein GCAGAAAGCAATGAGAGAAATCC TTGGGAAAAACACAACGGAACCT ACTAAGAAGAGGTCCTACTTTGT GAATTTTCTAGCCGTGTCCAGCG GCCGC T11-6 ACTAGTGGCCGGCCAACGTATAA zinc finger Unknown as AGTAAATATTTCTAAAGCAAAAA protein 258 tumour CTGCTGTGACGGAGCTCCCTTCT antigen GCAAGGACAGATACAACACCAGT TATAACCAGTGTGATGTCATTGG CAAAAATACCTGCTACCTTATCT ACAGGGAACACTAACAGTGTTTT AAAAGGTGCAGTTACTAAAGAGG CAGCAAAGATCATTCAAGATGAA AGTACACAGGAAGATGCTATGAA ATTTCCATCTTCCCAATCTTCCC AGCCTTCCAGGCTTTTAAAGAAC AAAGGCATATCATGCAAACCCGT CACACATCCCAGCGGCCGC T11-9 ACTAGTCGGGCCGGCCAACTTCG EST ATTTAGTGATCATGCCGTGTTGA hypotetical AATCCTTGTCTCCTGTAGACCCA human protein GTGGAACCCATAAGTAATTCAGA ACCATCAATGAATTCAGATATGG GAAAAGTCAGTAAAAATGATACT GAAGAGGAAAGTAATAAATCCGC CACAACAGACAATGAAATAAGTA GGACTGAGTATTTATGTGAAAAC TCTCTAGAAGGTAAAAATAAAGA TAATTCTTCAAATGAAGTCTTCC CCCAATATGCCAGCGGCCGC T11-3 ACTAGTCGGGCCGGCCAACGCAA EST GCAAAGTTTCCCAAATTCAGATC KIAA0697 CTTTACATCAGTCTGATACTTCC protein AAAGCTCCAGGTTTTAGACCACC ATTACAGAGACCTGCTCCAAGTC CCTCAGGTATTGTCAATATGGAC TCGCCATATGGTTCTGTAACACC TTCTTCAACACATTTGGGAAACT TTGCTTCAAACATTTCAGGAGGT CAGATGTACGGACCTGGGGCACC CCTTGGAGGAGCACCCACCAGCG GCCGC T5-2 ATGGGTACTAGTCGGGCCGGCCA human genome ACCCACTTCAGAAAACTATTTGG DNA CAGTAACTACTAAAACTAAACAT AAGCATAGCCTACAACCCAGTAA TGCCAGTATTTCACTCCTAGGTA TATACCCAACCCCCAGCGGCCGC T5-19 ACTAGTCGGGCCGGCCAACGTGA EST CACACAGACACATGCACATGTGA GTGTATGCGTGCACACACCCCAC CACACCTACAAATACCCCACCAG CGGCCGC

Clone T1-74, hitherto unknown, has the following sequence MGTSRPANREAKQLHHQPHSIELIQSSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T4-2, hitherto unknown, has the following sequence MGTSRPANSEVYKPTLLYSSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T4-11, hitherto unknown, has the following sequence MGTSGRPTVGFTLDFTVDPPSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T4-19, hitherto unknown has the following sequence MGTSRAGQLYRTTLTYTSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T1-12, hitherto unknown, has the following sequence MRYYTATKTYELMLDATTQTSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T1-39, hitherto unknown, has the following sequence MRVIDRAQAFVDEIFGGGDDAHNLNQHNSSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T5-8 is known as a fragment of AKAP protein, but has never been identified as a tumour antigen. Said clone has the sequence MGTSRAGQQREQEKKRSPQDVEVLKTTTELFHSNEESGFFNELEA LRAESVATKAELASYKEKAEKLQEELLVKETNMTSLQKDLSQVRD HQGRG and its use as a tumour antigen is part of the invention described herein.

Clone T5-13 is known as as a fragment of SOS1 protein, but has never been identified as a tumour antigen. Said clone has the sequence AGTSRAGQHAFEQIPSRQKKILEEAHELSEDHYKKYLAKLRSINPP CVPFFGIYLTNLLKTEEGNPEVLKRHGKELINFSKRRKVAEITGEIQ QYQNQYCLRVESDIKRFFENLNPMGNSMEKEFTDYLFNKSLEIEP RKPSGR and its use as a tumour antigen is part of the invention described herein.

Clone T5-15 is known as a fragment of EST protein KIAA1735, but has never been identified as a tumour antigen. Said clone has the sequence MGTSRAGQQERSLALCEPGVNPEEQLIIIQSRLDQSLEENQDLKKE LLKCKQEARNLQGIKDALQQRLTQQDTSVLQLKQELLRANMDKDE LHNQNVDLQRKLDERTQRP and its use as a tumour antigen is part of the invention described herein.

Clone T5-18 is known as as a fragment of a mic oncogen, alternative frame, but has never been identified as a tumour antigen. Said clone has the sequence MGTSRAGQPMSGHGSFQEVPRLHTSAQLRSASLHSEGLSCCQEGQVGQCQSPETDQQQPKMHQPSGR and its use as a tumour antigen is part of the invention described herein.

Clone T6-1 is known as a fragment of protein kinase C-binding protein, identified as cutaneous T-cell lymphoma tumour antigen (Eichmuller S., et al. PNAS, 2001; 98; 629-34). The present invention has identified it as breast cancer tumour antigen. Said clone has the sequence TSRAGQRYEKSDSSDSEYISDDEQKSKNEPEDTEDKEGCQMDKEP SAVKKKPKPTNPVEIKEELKSTPPA and its use as a breast cancer tumour antigen is part of the invention described herein.

Clone T6-2 hitherto unknown, has the following sequence TSRAGQLARIPSVTASEQGRT; it is a tumour antigen and as such is part of the invention described herein.

Clone T6-6 is known as a fragment of homologous to PI-3-kinase related kinase SMG-1, but has never been identified as a tumour antigen. Said clone has the sequence TSGPANAAPPSADDNIKTPAERLRGPLPPSADDNLKTPSERQLTPLPPAAAK; it is a tumour antigen and as such is part of the invention described herein.

Clone T6-7 is known as a fragment of fucosyltransferase, but has never been identified as a tumour antigen. Said clone has the sequence TSRAGQRELGRTGLYPSYKVREKIETVKYPTYPEAEK; it is a tumour antigen and as such is part of the invention described herein.

Clone T7-1 is known as a fragment of EST protein KIAA1288, but has never been identified as a tumour antigen. Said clone has the sequence TSVLEPTKVTFSVSPIEATEKCKKVEKGNRGLKNIPDSKEAPVNLC KPSLGKSTIKTNTPIGCKVRKTEIISYPSTSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T9-22 is known as a fragment of similar (50% of identity) to reverse trascriptase homolog protein, but has never been identified as a tumour antigen. Said clone has the sequence MDLTAVYRTFHPTITEYTFYLTVHGTFSKIDHMIGHKTSLNKSKKTEIISSTLSDHSGIKLE SNSKRNPQIHASGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T1-5 is known as a fragment of an unnamed transmembrane theoretical protein, but has never been identified as a tumour antigen. Said clone has the sequence MPIDVVYTWVNGTDLELLKELQQVREQMEEEQKAMREILGKNTTEPTKKRSYFVNFLAVSSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T11-6 is known as a fragment of the zinc finger protein 258, but has never been identified as a tumour antigen. Said clone has the sequence TSGRPTYKVNISKAKTAVTELPSARTDTTPVITSVMSLAKIPATLSTGNTNSVLKGAVTKEAAKIIQDESTQEDAMKFPSSQSSQPS RLLKNKGISCKPVTHPSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T11-9 is known as a fragment of a hypotetical human protein, but has never been identified as a tumour antigen. Said clone has the sequence TSRAGQLRFSDHAVLKSLSPVDPVEPISNSEPSMNSDMGKVSKNDTEEESNKSATTDNEISRTEYLCENSLEGKNKDNSSNEVF PQYASGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T11-3 is known as a fragment of EST protein KIAA0697, but has never been identified as a tumour antigen. Said clone has the sequence TSRAGQRKQSFPNSDPLHQSDTSKAPGFRPPLQRPAPSPSGIVNMDSPYGSVTPSSTHLGNFASNISGGQMYGPGAPLGGAPTSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T5-2 is known as a fragment of human genome DNA, but has never been identified as a tumour antigen. Said clone has the sequence MGTSRAGQPTSENYLAVTTKTKHKHSLQPSNASISLLGIYPTPSGR; it is a tumour antigen and as such is part of the invention described herein.

Clone T5-19 is known as a fragment of EST protein, but has never been identified as a tumour antigen. Said clone has the sequence TSRAGQRDTQTHAHVSVCVHTPHHTYKYPTSGR; it is a tumour antigen and as such is part of the invention described herein.

It will be understood that, according to the present invention, sequences which are part of known proteins but were unknown as tumor antigen are an object of the present invention as far as their use as tumor antigens is concerned. In the same way, an object of the present invention are the use as tumour antigen of the sequence, or of the entire or part of the product of the gene encoding for said sequence.

The phage clones characterised by means of pick-blot analysis and for which specific reactivity had been demonstrated with sera from patients suffering from breast tumours were amplified and then analysed with a large panel of positive and negative sera. After this ELISA study, the cDNA clones regarded as corresponding to specific tumour antigens were cloned in different bacterial expression systems (protein D and/or GST), for the purposes of better determining their specificity and selectivity. To produce the fusion proteins each clone was amplified from a single plaque by PCR using the following oligonucleotides: K84 5′-CGATTAAATAAGGAGGAATAAACC-3′ and K86 5′-CTCTCATCCGCCAAAACAGCC-3′. The resulting fragment was then purified using the QIAGEN Purification Kit, digested with the restriction enzymes SpeI and NotI and cloned in plasmid pKM4-6H to produce the fusion protein with D having a 6-histidine tail, or in vector pGEX-SN to generate the fusion with GST. The corresponding recombinant proteins were then prepared and purified by means of standard protocols (Sambrook, J., Fritsch, E. F. & Maniatis, T. (1989) Molecular Cloning, Cold Spring Harbor Laboratory Press, Cold Spring Harbor).

The following table gives, by way of an example, the reactivities with negative and positive sera of a number of selected clones, assayed in the form of phage or fusion protein preparations: Lambda phage Lambda Reactivity Reactivity of reactivity with phage of fusion fusion positive sera reactivity protein D protein D with Name (number positive/ with with positive negative sera of total number negative sera (* for (* for GST clone assayed) sera GST fusion) fusion) T1-2  1/20  0/9 T1-17  1/10  0/0  * 2/16 * 0/15 T1-8  1/10  0/0    1/13   0/15 T1-6  1/10  0/0 T1-101  /20  0/1 T1-52  7/41  0/20   13/53   3/24 T1-35  4/10 14/21 T1-10  1/10  0/0 T1-39 11/34  0/26 Non-reactive T1-12 23/72  0/31 Non-reactive T1-32 17/72  0/31 * 10/72 * 1/31 T1-74 29/72  2/27 * 21/72 * 4/32 T4-2 11/18  0/17    9/28   1/31 T4-11  4/21  0/26    8/70   0/30 T4-19  5/20  0/26   12/70   0/30

For the purposes of demonstrating the efficacy of the tumour antigens selected for recognising tumour cells and thus for the detection and diagnosis of pathological abnormalities, mice were immunised to induce an antibody response to a number of the clones selected.

The mice were immunised by giving seven administrations of the antigen over a period of two months, using as immunogens the fusion proteins D1-52, D4-11 and D4-19, corresponding to the fusions of the sequences of clones T1-52, T4-11 and T4-19 with protein D. Each time, 20 μg of protein were injected (intraperitoneally or subcutaneously) per mouse in CFA, 20 μg in IFA, 10 μg in PBS and four times 5 μg in PBS for each of the three proteins. For the purposes of checking the efficacy of immunisation to the sequence of the tumour antigen, the sera of the immunised animals were assayed against the same peptide sequences cloned in different contexts, in order to rule out reactivity to protein D.

In the case of D1-52, the sera of the immunised mice were assayed with the fusions with GST (GST1-52), whereas in the cases of D4-11 and D4-19 the corresponding peptide sequences were cloned in vector pC89 (Felici et al. 1991, J. Mol. Biol. 222:301-310) and then tested as fusions to pVIII (major coat protein of filamentous bacteriophages). The results of ELISA with the sera of the immunised animals showed that effective immunisation was obtained in the cases of D1-52 and D4-11, and thus the corresponding sera were assayed for the ability to recognise tumour cells. To this end, the cell line MCF7 was used, and analysis by FACS demonstrated that antibodies present in both sera (anti-D1-52 and anti-D4-11) are capable of specifically recognising breast tumour MCF7 cells, and not, for instance, ovarian tumour cells, while this recognition capability is not present in preimmune sera from the same mice. 

1-19. (Canceled)
 20. Specific tumor antigens obtainable by selection of cDNA libraries with sera, characterised in that said selection is accomplished with the phage display technique.
 21. Tumor antigens according to claim 20, in which said selection is accomplished by means of the SEREX technique (serological analysis of autologous tumor antigens through expression of recombinant cDNA).
 22. Tumor antigens according to claim 20, in which said selection is accomplished by means of the affinity selection technique.
 23. Tumor antigens according to claim 20, in which said libraries are obtained from tumor biopsies.
 24. Tumor antigens according to claim 20, in which said libraries are obtained from cultured tumor cell lines.
 25. Antigen according to claim 20 selected from the group consiting of: MGTSRPANREAKQLHHQPHSIELIQSSGR; (SEQ ID NO: 49) MGTSRPANSEVYKPTLLYSSGR; (SEQ ID NO: 50) MGTSGRPTVGFTLD FTVDPPSGR; (SEQ ID NO: 51) MGTSRAGQLYRTTLTYTSGR; (SEQ ID NO: 52) MGTSRAOQLHAFPLHSTTLYYTTPSGR; (SEQ ID NO: 48) MRYYTATKTYELMLDATTQTSGR; (SEQ ID NO: 53) and MRVIDRAQAFVDEIFGGGDDAHNLNQHNSSGR. (SEQ ID NO: 54)


26. A tumor antigen of a sequence or entire sequence, or nucleic acid sequence encoding said antigen or entire sequence, said entire sequence being selected from the group consisting of: VLVAGQRYQSRSGHDQKNHRKHHGKKRMKSKRST (SEQ ID NO: 46) SLSSPRNGTSGR, MGTSRAGQQREQEKKRSPQDVEVLKTTTELFHSN (SEQ ID NO: 55) EESGFFNELEALRAESVATKAELASYKEKAEKLQ EELLVKETNMTSLQKDLSQVR DHQGRG, AGTSRAGQHAFEQIPSRQKKILEEAHELSEDHYK (SEQ ID NO: 56) KYLAKLRSTNPPCVPFFGIYLTNLLKTEEGNPEV LKRHGKELINFSKRRKVAEITGEIQQYQNQYCLR VESDTKRFFENLNPMGNSMEKEFTDYLFNKSLEI EPRKPSGR, MGTSRAQQQERSLALCEPGVNPEEQLIIIQSRLD (SEQ ID NO: 57) QSLEENQDLKKELLKCKQEARNLQGIKDALQQRL TQQDTSVLQLKQELLRANMDKD ELHNQNVDLQR KLDERTQRP, MGTSRAGQPMSGHGSFQEVPRLHTSAQLRSASLH (SEQ ID NO: 58) SEGLSCCQEGQVGQCQSPETDQQQPKMHQPSGR, TSRAGQLARIPSVTASEQGRT, (SEQ ID NO: 60) TSGPANAAPPSADDNIKTPAERLRGPLPPSADDN (SEQ ID NO: 61) LKTPSERQLTPLPPAAAK, TSRAGQRELGRTGLYPSYKVREKIETVKYPTYPE (SEQ ID NO: 62) AEK, TSVLEPTKVTFSVSPIEATEKCKKVEKGNRGLKN (SEQ ID NO: 63) IPDSKEAPVNLCKPSLGKSTIKTNTPIGCKVRKT EIISYPSTS GR, MDLTAVYRTFHPTITEYTFYLTVHGTFSKIDHMI (SEQ ID NO: 64) GHKTSLNKSKKTEIISSTLSDHSGIKLESNSKRN PQHIASGR, MPIDVVYTWVNGTDLELLKELQQVREQMEEEQKA (SEQ ID NO: 65) MREILGKNTTEPTKKRSYFVNFLAVSSGR, TSGRPTYKVNISKAKTAVTELPSARTDTTPVITS (SEQ ID NO: 66) VMSLAKIPATLSTGNTNSVLKGAVTKEAAKIIQD ESTQEDAMKFPSSQSSQPSRLLKNK GISCKPVT HPSGR, TSRAGQLRFSDHAVLKSLSPVDPVEPISNSEPSM (SEQ ID NO: 67) NSDMGKVSKNDTEEESNKSATTDNEISRTEYLCE NSLEGKNKDNSSNEVFPQYASGR, TSRAGQRKQSFPNSDPLIIQSDTSKAPGFRPPLQ (SEQ ID NO: 68) RPAPSPSGIVNTVIDSPYGSVTPSSTHLGNFASN ISGGQMYGPGAPLGGAPTSGR, MGTSRAGQPTSENYLAVTTKTKHKHSLQPSNASI (SEQ ID NO: 69) SLLGIYPTPSGR, and TSRAGQRDTQTHAHVSVCVHTPHHTYKYPTSGR. (SEQ ID NO: 70)


27. An antigen of a sequence or of the entire sequence, or nucleic acid sequence encoding said antigen or entire sequence, said entire sequence being selected from the group consisting of: TSRAGQRYEKSDSSDSEYISDDEQKSKNEPEDTE (SEQ ID NO: 59) DKEGCQMDKE-PSAVKKKPKPTNPVEIKEELKST PPA, and MGTSRAGQLVEELDKVFSQEREDVLAGMSGKSSF (SEQ ID NO: 49) QRSEGDFLLRSLTSGR.


28. A method of manufacturing a medicament for treatment of tumors comprising preparing an antigen of claim 20 in the form of a medicament.
 29. Specific ligand for an antigen of claim
 20. 30. Anti-antigen antibody of an antigen of claim
 20. 31. A medicament comprising a ligand for and/or anti-antigen antibody of an antigen of claim 20 in a diluent.
 32. A carrier for an active agent for the treatment of tumors comprising a ligand for and/or anti-antigen antibody of an antigen of claim
 20. 33. An expression/display vector (λKM4) which expresses and/or displays an antigen of claim
 20. 34. An antitumor vaccine comprising at least an antigen of claim
 20. 35. An antitumor medicament comprising a ligand of claim
 29. 36. An antitumor medicament comprising an antibody of claim
 30. 37. Vaccine for treating breast cancer comprising the antigen of claim 27 and/or a specific ligand thereof and/or a specific antibody thereof. 